1. Field of the Invention
This invention relates to multi-component compositions having utility as cleaners, delivery systems, solvent systems and the like. In particular, the invention relates to a composition including both fluorinated and non-fluorinated components, which can form single phase combinations and permit solubility of highly fluorinated, as well as partially fluorinated, compounds which are ordinarily not soluble in polar or most hydrocarbon solvent materials.
2. Brief Description of Related Technology
In recent years, the use of both chlorinated and chlorofluoro hydrocarbons (xe2x80x9cCFCsxe2x80x9d) have been substantially lessened due to their deleterious effect on the environment and stringent regulations have been promulgated throughout the world to accelerate their phase-out. Many of these materials are not only toxic but are believed responsible for ozone-depletion. Thus, notwithstanding their usefulness as solvents, strict laws regarding handling, labeling and disposal have been passed to discourage further use. Finding acceptable alternatives to these solvents has been an extremely difficult task, particularly to find solvents or solvent systems which possess a balance of important properties required for many industrial applications such as high chemical stability, non-flammability, low toxicity and low volatile organic solvent (xe2x80x9cVOCxe2x80x9d) content, and yet which are sufficiently volatile to readily evaporate once applied. In particular, it has been difficult to find solvent systems for highly fluorinated compounds such as perfluorocarbons (xe2x80x9cPFCsxe2x80x9d) and the like because of their extremely low solubility, if any, in conventional solvent materials such as polar solvents and in most hydrocarbons, including acids and bases.
It is desirable that solvent systems for delivery of a material, such as a highly fluorinated compound, to or cleaning a highly fluorinated compound from a substrate, possess a balance of characteristics in addition to their ability to solubilize or otherwise combine in a compatible way with the material. For example, solvent systems desirably balance non-ozone depleting and non-flammable characteristics with sufficient volatility characteristics to be useful as cleaners or delivery systems. Although many materials possess the ability to act as volatile solvents, most have been too flammable or toxic to serve as suitable replacements for conventional ozone-depleting compounds such as chlorinated hydrocarbons or CFCs. For example, materials such as heptane, acetone, methylethyl ketone, isopropanol, and methanol are excellent solvents for many substances and possess good volatility, i.e., low flash point temperatures and high vapor pressures, but these materials are extremely flammable. Other substances such as isoparaffins and propylene glycol ether are less flammable, but do not exhibit adequate solvent performance properties for materials such as highly fluorinated compounds.
PFCs are essentially non-toxic, non-flammable, and thermally and hydrolytically stable alternatives to CFCs. However, the drawback of PFCs is the inability to form solutions with most substances. Moreover, the cost of PFCs is extremely high and commercially unattractive for most industrial applications. Thus, their suitability as cleaners or as carriers in delivery systems has been largely stilted.
Attempts have been made to combine perfluorinated compounds with solvents to form azeotropic compositions. For example, U.S. Pat. Nos. 5,401,429, 5,484,489, 5,594,601, and 5,744,436 disclose azeotropic compositions which include a perfluorinated cycloaminoether and an organic solvent, such as tetrafluorocyclobutane, tetrafluorodichloroethane, cyclopentane, cyclohexane and the like. These compositions are disclosed as being cleaners for electronic printed circuit boards, magnetic media, disk drives, medical articles and the like. The article to be cleaned is generally contacted with the azeotropic composition while the composition is boiling or otherwise agitated. Certain of the azeotropic compositions disclosed were used as vapor degreasing compositions.
U.S. Pat. No. 5,403,514 discloses a non-flammable solvent composition which comprises 40% by volume or more of a non-flammable perfluoro organic compound. The other portion of the composition is a flammable organic compound which is suitable as a degreasing solvent.
A single phase liquid composition comprising 2-20% benzotrifluoride, 5-50% glycol ether, 2-40% alkanol and 7-56% water is disclosed in U.S. Pat. No. 5,744,437. This composition is described as being effective in cleaning hard surfaces, stripping paint, and as a carrier.
U.S. Pat. No. 5,756,002 discloses a two-part, single-phase cleaning solvent which is a combination of a selected fluorinated compound in amounts of 3 to about 20 weight %, with the remainder being benzotrifluoride. The ""002 patent describes this blend as being non-flammable and being a better cleaner than the fluorinated compound itself. The composition can optionally contain up to 15 weight % alkanol from C1 to C4.
Fluorinated oils are not soluble in traditional solvents. Their utility in industry is widespread however, due to their properties of being excellent lubricants under severe chemical conditions and at elevated temperatures. It is well-known that their performance properties are beyond those of most hydrocarbon based lubricants. Whereas elevated temperatures, aggressive chemicals, flammable conditions and airborne contaminants can quickly exceed the performance capabilities of many hydrocarbon lubricants, this is not the case for fluorinated lubricants.
It is desirable to incorporate the advantages of a fluorinated base stock, i.e., a carrier system, with those of fluorinated oils to provide a lubricant composition for applications where temperature, flammability, or other factors exceed the performance of conventional petroleum lubricants. Moreover, it is desirable to find a penetrating lubricant composition that is non-flammable, non-ozone depleting and which can be used in areas where fire hazards may exist.
A common generally acceptable principle in organic chemistry with respect to solvents is stated by Morrison and Boyd in Organic Chemistry, page 31, Allyn and Bacon, 3rd ed. (1973). This rule states that for the most part xe2x80x9clike dissolves likexe2x80x9d. Based on this principle, highly fluorinated oils could be dissolved by highly fluorinated solvents. In fact some perfluorinated oils are known to be soluble in fully or partially fluorinated solvents such as decafluoropeutane and methoxy-nonafluorobutane. However, highly fluorinated solvents are extraordinarily expensive and use of them as the sole solvent would not be commercially feasible. The present invention utilizes the affinity of two different fluorinated components in combination with an alkane to produce a cost-effective solvent system useful with perfluorinated and partially fluorinated oils, as well as other materials.
It is apparent that there is a need for a composition which can serve as a solvent for difficult to dissolve materials, i.e., fluorinated compounds, and which can have a wide range of applications including use as a cleaner or a delivery system for such materials. Moreover, there is a need for a low cost composition which also possesses a balance of characteristics with respect to volatility, low toxicity, non-ozone depleting properties and non-flammability as discussed herein. The present invention provides compositions which meet these and other needs.
The present invention is directed to compositions which comprise a combination of at least three componentsxe2x80x94the first component including a fluorinated compound; the second component including a fluorinated aromatic compound; and the third component including an alkane. The first and second fluorinated components are intended to be different. This combination of components allows for compositions to be formulated which are useful as cleaners and/or delivery systems as well as solvent systems for a variety of materials. In particular, the compositions of the present invention have excellent applicability for use with highly fluorinated materials, such as fluorinated oils, either as a cleaner to remove the fluorinated materials from a substrate or as a carrier to deposit the fluorinated material onto a substrate.
The present invention further includes a composition including a material such as a fluorinated oil, and a combination of components compatible with the fluorinated material the combination including a first component comprising a fluorinated compound; a second component different from the first comprising a fluorinated aromatic compound; and a third component comprising an alkane.
The compositions of the present invention once formed are most desirably in a single phase system. Single phase systems allow for more effective cleaning compositions and delivery systems to be made, particularly when difficult to dissolve materials such as fluorinated oils requiring removal from or delivery to a substrate are involved. However, while the single phase system is the most desirable physical form of the present compositions, emulsions, dispersions or other combinative forms may be formulated to meet a wide variety of applications.
The inventive compositions can be further combined with a propellant and packaged in aerosol containers. Accordingly, the present invention also contemplates articles of manufacture which include a container for packaging a flowable composition; a flowable composition within the container, the composition including a combination of a first component comprising a fluorinated compound, a second component different from the first comprising a fluorinated aromatic compound, and a third component comprising an alkane. A method of cleaning an oil from a substrate is also contemplated within the present invention and includes the steps of providing a composition having a first component comprising a fluorinated compound, a second component different from the first comprising a fluorinated aromatic compound, and a third component comprising an alkane; and applying the composition to an oil-bearing substrate to remove the oil from the substrate.
A method of manufacturing a fluorinated oil composition is also described including the steps of combining of a first component comprising a fluorinated compound; a second component different from the first comprising a fluorinated aromatic compound; a third component comprising an alkane; and a fluorinated oil.
In one embodiment, the present invention relates to a composition, which includes a combination of at least three components. The first component includes a fluorinated compound. The second component is different from the first and includes a fluorinated aromatic compound. The third component includes an alkane.
Among the most desired fluorinated compounds useful for the first component are those which contain a fluorinated portion, which portion is substantially soluble in a fluorinated oil. In effect, the fluorinated portion renders the compound more compatible with or miscible in fluorinated materials due to their respective fluorinated parts. While a broad range of fluorinated compounds are useful, most desired as the first component are fluorinated compounds selected from the group consisting of fluorinated ethers, fluorinated alkanes and combinations thereof. Among this group, the first fluorinated component is selected from fluorinated alkyl groups having from 4 to 10 carbon atoms, fluorinated ether compounds corresponding to formula R1OR2, where R1 and R2 may be the same or different and are alkyl groups having from 1 to 4 carbon atoms, and combinations thereof.
Among the desirable classes of fluorinated compounds useful for the first component are the partially fluorinated ethers. This class of fluorinated ethers is soluble in perfluorinated oils in virtually all proportions. Among the commercially available partially fluorinated ethers particularly useful is methyl nonafluorobutyl ether, having the formula F3CCF2CF2CF2OCH3.
Among the fluorinated alkanes useful in the first component of the composition include CF3CHFCHFCF2CF3, CF3CH2CHFCF2CF3, CF3CHFCH2CF2CF3, CF3CHFCHFCF2CF2CF3, CF3CH2CHFCF2CF2CF3, CF3CHFCH2CF2CF2CF3, CF3CF2CH2,CHFCF2CF3, CF3CF2CHFCHFCF2CF2CF3, CF3CHFCHFCF2CF2CF2CF3, CF3CHFCH2CF2CF2CF2CF3, CF3CH2CHFCF2CF2CF2CF3, CF3CF2CHFCH2CF2CF2CF3, and CF3CF2CH2CHFCF2CF2CF3. Combinations of these compounds are contemplated. Decafluoropentane has been found to be particularly useful.
The second component of the compositionxe2x80x94which includes a fluorinated aromatic compoundxe2x80x94desirably includes a fluorinated benzene compound selected from the group consisting of benzotrifluoride, p-chlorobenzotrifluoride, dichlorobenzotrifluoride, trifluorotoluene and combinations thereof. Benzotrifluoride and p-chlorotrifluoride have been found to be particularly effective, alone or in combination. The second component may only be partially soluble or substantially insoluble in fluorinated oil.
The third component of the composition includes an alkane which desirably corresponds to the general structural formula CnH2n+2 wherein n is an integer from 5 to 20. Hexane has been found to be particularly useful.
It has been discovered that the relative amounts of the three components of the composition can be adjusted to provide a single phase solvent system. This is quite surprising in that alkanes are only slightly soluble at best in either of the other fluorinated components. The present invention allows for a significant percentage of the composition to be an alkane. Since the alkane is inexpensive relative to fluorinated solvent compounds such as perfluoroalkyl-polyethers, the inclusion of the alkane allows for a significant reduction in cost of the overall composition. Moreover, the presence of an alkane solvent in the composition further provides the ability to dissolve petroleum oils, greases and organic residue to a certain degree. The ability to form a stable single-phase is even further surprising in that many of the useful fluorinated aromatic compounds used as a second component in the inventive composition are not readily soluble in the partially or fully fluorinated oils used in oil-containing embodiments of the present invention. However, when their proportions are adjusted to within certain ranges, they form a single phase multi-component solvent system which exhibits phase stability.
A single phase composition facilitates the delivery of each of the components in their relative proportions, either for cleaning purposes or when used as a vehicle to deliver other active materials such as fluorinated oils. Thus, in its most desired form, the composition of the present invention is as a whole substantially soluble in or substantially solubilizes fluorinated oil.
For purposes of the present invention, the term xe2x80x9cnon-flammablexe2x80x9d will mean a flash-point of greater than about 200xc2x0 F. (94xc2x0 C.), whereby heating is required for the material to catch fire; and the term xe2x80x9cflammablexe2x80x9d will mean the material is ignitable with a spark rather than by heating, and having a flash-point of about less than 100xc2x0 F. (38xc2x0 C.). Generally, compounds which have a flash-point between 140-200xc2x0 F. (60xc2x0-93xc2x0 C.) are classified as combustible. The above definitions are believed to be generally accepted ones in accordance with those set by the U.S. Department of Transportation (DOT).
To form a single phase solvent system, the upper limit of the first component comprising a fluorinated compound, to the combination of the second and third components comprising a fluorinated aromatic compound and an alkane is respectively about 1:1.2. Amounts greater than this are useful, of course, if the single phase is not the desired state. For example, if phase separation is suitable for the particular application, where the addition of a compatibilization component or simple agitation would result in an emulsion, dispersion or suspension, the proportion of the first component can be outside the upper limit.
It is contemplated that additional components may be added to cause what would ordinarily be a multi-phase system to become a single-phase system. Other methods for obtaining a single phase include controlling the ambient conditions of temperatures and pressure in the dispensing container to cause the components to solubilize in each other or be more miscible. The relative amounts of the third component comprising an alkane, to the second component comprising a fluorinated aromatic compound, have a maximum ratio of about 1:1.5 in order to obtain a single phase. Again, amounts outside this maximum ratio may be useful provided the desired result is not to obtain a single phase system. Thus, in compositions of the present invention intended to obtain a single phase system, i.e., a multi-component solvent composition, the ratio of the first component to the combination of the second two components and the ratio of the second component to the third component are generally within the maximum ratio values given above. Moreover, in embodiments where the composition is to include a propellant, the propellant can also be chosen so that it is soluble or otherwise compatible with the overall composition such that it can be dispensed in a single phase, thereby avoiding separation of the propellant from the other components in the container during storage.
Fluorinated compounds useful as the first component can be present in amounts of about 25% by weight of the three component composition, or greater. In one desired embodiment, the first component is present in amounts of about 25% to about 60% and more desirably about 30% to about 45% by weight of the three component composition. When calculated on a total weight percent basis, i.e., including oils, additives, propellants and the like, the first component may be present in amounts of about 15% and 50% by weight, and more desirably in amounts of about 17% to about 30% by weight of the total composition.
The second componentxe2x80x94which includes the fluorinated aromatic compoundxe2x80x94is generally present in amounts of about 5% to about 50% by weight of the three component composition. In one desired embodiment, this component is present in amounts of about 5% to about 30% by weight of the three component composition. When calculated on a total composition weight percent basis, i.e., including oils, additives, propellants and the like, the second component may be present in amounts of about 5% to about 25% by weight of the total composition.
The third component comprising an alkane is generally present in amounts of at least 2% by weight, desirably in amounts of 15% to about 40% by weight, and more desirably in amounts of about 20% to about 30% by weight of the three component composition. When calculated on a total composition weight % basis, i.e., including oils, additives, propellants and the like, the third component may be present in amounts of about 5% to about 15% by weight of the total composition.
The compositions of the present invention can further include a fluorinated oil which is at least partially soluble and desirably soluble or otherwise miscible therein. A variety of fluorinated oils may be employed, including perfluoropolyether oils. Among the perfluoropolyether oils considered desirable are those which are perfluoroalkylpolyethers. For example, useful perfluoroalkylpolyether oils may be selected from CF3CF2CF2Oxe2x80x94[CF (CF3)CF2xe2x80x94Oxe2x80x94]nxe2x80x94CF2CF3, CF3Oxe2x80x94[CF(CF3) CF2xe2x80x94Oxe2x80x94]yxe2x80x94[CF2xe2x80x94O]mCF3, CF3Oxe2x80x94[CF2CF2xe2x80x94Oxe2x80x94]zxe2x80x94[CF2xe2x80x94Oxe2x80x94]CF3, CF3CF2xe2x80x94[CF2xe2x80x94Oxe2x80x94]qCF2 Cf3, halocarbons containing the repeating group xe2x80x94(CF2CFCl)rxe2x80x94, where r is an integer from 2 to 10 and having an average molecular weight of from about 230 to about 1200 and combinations thereof; where n is an integer from 0 to 60; y is an integer from 0 to 60; m is an integer from 0 to 60; z is an integer from 0 to 60; p is-an integer from 0 to 60; and q is an integer from 0 to 60. Of particular utility is the fluorinated oil corresponding to the formula F[CF(CF3)CF2O]nCF2CF3, where n is an integer from 10 to 60. This fluorinated oil is commercially available under the trademark KRYTOX sold by DuPont, Wilmington, Del.
The fluorinated oil may be present in the composition in any useful amount. Desirably, the fluorinated oil is present in amounts of about 18% to about 90% by weight of the total composition and desirably in amounts of about 20% to about 50% by weight. As previously mentioned, in one desirable embodiment the oil is in solution with the combination of the other three required components, although it is contemplated that dispersions, emulsions, suspensions or other combinative forms may be used. Solutions or single phase systems have advantages in many applications over multi-phase systems. The present invention derives the benefits of a single-phase in a cost effective manner. Whereas highly fluorinated compounds may serve as solvents for fluorinated oils, such solvents are extraordinarily expensive and therefore their commercial utility in high volume applications is greatly lessened. The present invention allows for multi-component, single-phase solvent systems to be made in which the fluorinated oil is soluble therein and the cost of such systems is a fraction of systems having single component highly fluorinated materials.
Compositions of the present invention can be formulated into aerosol compositions by the addition of suitable propellants. As previously mentioned, if a single-phase system is desired, it is often advantageous to choose a propellant which is also soluble or miscible with the remainder of the composition. Suitable propellants for use in the present invention include, without limitation, carbon dioxide, isobutane, dimethylether, 1,1,1,2-tetrafluoroethane and combinations thereof. When present, the propellant may be utilized in amounts sufficient to facilitate delivery of the composition from an aerosol container. For example, the propellant may be present in amounts of about 1% to about 50%, and most desirably in amounts of about 25% to about 35% by weight of the total composition.
In one particular embodiment of the present invention, there is provided a fluorinated oil aerosol composition including a) a fluorinated oil; b) a combination of components compatible with the oil; and c) an aerosol propellant. The combination of components of b) includes i) a first component including a fluorinated compound present in amounts of about 25% or greater by weight of the combination; ii) a second component including a fluorinated aromatic compound present in amounts of about 5% to about 10% by weight of the combination; and iii) a third component including an alkane.
Among the fluorinated oils useful in this aerosol composition include those previously mentioned, as well as others known in the art. As mentioned above, the three component combination of the present invention may have a first component selected from fluorinated alkanes having from 4 to 10 carbons, a fluorinated alkylether corresponding to the general formula R1OR2, where R1 and R2 may be the same or different and are fluorinated alkyl groups having from 1 to 4 carbon atoms and combinations thereof. The second component is desirably selected from benzotrifluoride, p-chlorobenzotrifluoride, dichlorobenzotrifluoride, trifluorotoluene and combinations thereof. The alkane may be selected from compounds which correspond to the general formula CnH2n+2, where n is an integer from 2 to 20. The fluorinated oil aerosol compositions may have a variety of other additives included, as will be discussed herein.
The compositions of the present invention may be used for a variety of products and applications. For example, among those types of products contemplated include solvent systems with particular application on materials which are difficult to dissolve in conventional solvents, such as fluorinated materials and particularly fluorinated oils. The inventive compositions may be used to deliver fluorinated oils onto a substrate and quickly volatilize to deposit the oil thereon. Other products include use as cleaning compositions, such as degreasing compositions, whereby oils or greases, and particularly fluorinated oils, can be readily removed from a substrate by application of the inventive composition.
Due to the relative solubility of the components of compositions made in accordance with the present invention, these compositions form particularly effective aerosol products which are capable of delivering the components in their relative proportions. Thus, there is contemplated in an article of manufacture which includes a container for packaging a flowable composition, the flowable composition including the aforementioned three component combination of a first fluorinated compound, a second different fluorinated aromatic compound and an alkane. The container for such an article of manufacture may be any conventional container known to the art. Of particular utility are containers which are suitable for spraying the composition, such as aerosol containers having a nozzle designed to release the composition under pressure. One particular aerosol container which is contemplated includes an outer housing and a flexible bladder contained therein. The external wall of the bladder and the internal wall of the outer housing define a space in which a propellant can be contained. The bladder can contain the compositions of the present invention and may be designed to be permeable to the propellant. Alternatively, the bladder itself can provide the compressive force necessary to dispense its contents.
The invention compositions of the present invention may also include a number of additives. Non-limiting examples of useful additives include compounds and classes of compounds which fall into the categories of anti-wear and extreme pressure additives, friction or lubricity modifiers, corrosion inhibitors, oxidation inhibitors and the like. These materials can be included in amounts sufficient to impart their intended function and effect.
Among those useful anti-wear and extreme pressure additives are zinc dialkyldithiophosphate, molybdenum disulfide, tricresyl phosphate, alkyl and aryl disulfides, polysulfides, dithiocarbamates, sulfurized fats, chlorinated paraffins and non-chlorinated replacements. Combinations of these additives are also contemplated.
Among the friction or lubricity modifiers, useful are graphite, zinc oxide and polytetrafluoroethylenes. Combinations of these modifiers are also contemplated.
Corrosion inhibitors useful in the present invention include long-chain amines, alkyl succinic acids, mildly polar organic acids such as the salts of benzoic acids, amine salts, sodium nitrite, sodium molybdenate, sodium sulfonate, calcium sulfonate, organic phosphates, polyhydric alcohols, dicyclohexylamine, triazole derivatives and cycloparaffin, e.g., naphthenate salts. Combinations of these inhibitors are also contemplated.
Oxidation inhibitors included hindered amines, such as naphthyl (phenyl) amine and hindered phenols, such as di-tert-butyl-p-cresol and 2-naphthol. Combinations of these inhibitors are also contemplated.
Stabilizers, viscosity modifiers, odor masking agents, coloring agents, plasticizers, other conventional additives and combinations thereof may also be employed.
The aforementioned additional additives can be present in amounts sufficient to impart their intended effect.
In addition to being useful as a delivery system for oils, other active materials, i.e., materials which are intended to be carried by the inventive compositions for deposition onto a substrate may be employed. For example, adhesive promoter agents and promoter compositions may be included in the inventive compositions. The composition is applied to a substrate and permitted to volatilize thereby leaving behind the promoter component. The type of promoter component will depend for the most part on the type of adhesive composition to be employed as well as the type of substrate to be bonded. For example, cyanoacrylates, anerobics, acrylics, epoxies and olefins have classes of compounds which activate, accelerate or otherwise promote their cure and/or enhance adhesion.
While the aforementioned aerosol version of the present invention takes advantage of many of the soluble properties, other forms of applying the composition to a substrate may be employed. For example, spraying, dipping, brushing, swabbing, wiping, roller coating, and the like onto a substrate is contemplated.